Effects and Costs of Tracing Strategies on Nonresponse Bias in a Survey of Workers with Low-Back Injury

Declining rates of participation are an increasing challengefor studies that involve telephone surveys. This study examinedthe costs of a telephone survey methodology that used increasinglyintensive tracing methods to track a pool of claimants who hadsustained occupational back injuries. It also compared the respondentsample to people who refused the survey and/or were not locatedor contacted. 3,181 claimants were drawn from a database maintainedby the Missouri Division of Workers’ Compensation (DWC)and 1,475 completed a telephone interview. The DWC databaseprovided data reflecting monetary and disability outcomes forall potential participants; telephone interviews provided additionalself-reported data. More intensive tracing strategies improvedthe representativeness of the sample, yielding more women andminority participants. Relative to less intensive techniques,advanced tracing efforts located people whose DWC records weremore similar to claimants not located. While the hands-on tracingefforts reduced the apparent bias of the respondent sample,costs increased as tracing strategies intensified – over$98,000 was spent to trace 1,027 claimants who were never locatedor contacted. The results suggest some guidelines that may facilitatedecision-making for researchers and funders who must balancethe trade-off between costs and nonresponse bias when planningsurveys.